# revlog.py - storage back-end for mercurial
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Storage back-end for Mercurial.
This provides efficient delta storage with O(1) retrieve and append
and O(changes) merge between branches.
"""
from __future__ import absolute_import
import collections
import errno
import os
import struct
import zlib
# import stuff from node for others to import from revlog
from .node import (
bin,
hex,
nullid,
nullrev,
)
from .i18n import _
from . import (
ancestor,
error,
mdiff,
parsers,
templatefilters,
util,
)
_pack = struct.pack
_unpack = struct.unpack
_compress = zlib.compress
_decompress = zlib.decompress
_sha = util.sha1
# revlog header flags
REVLOGV0 = 0
REVLOGNG = 1
REVLOGNGINLINEDATA = (1 << 16)
REVLOGGENERALDELTA = (1 << 17)
REVLOG_DEFAULT_FLAGS = REVLOGNGINLINEDATA
REVLOG_DEFAULT_FORMAT = REVLOGNG
REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS
REVLOGNG_FLAGS = REVLOGNGINLINEDATA | REVLOGGENERALDELTA
# revlog index flags
REVIDX_ISCENSORED = (1 << 15) # revision has censor metadata, must be verified
REVIDX_DEFAULT_FLAGS = 0
REVIDX_KNOWN_FLAGS = REVIDX_ISCENSORED
# max size of revlog with inline data
_maxinline = 131072
_chunksize = 1048576
RevlogError = error.RevlogError
LookupError = error.LookupError
CensoredNodeError = error.CensoredNodeError
def getoffset(q):
return int(q >> 16)
def gettype(q):
return int(q & 0xFFFF)
def offset_type(offset, type):
return long(long(offset) << 16 | type)
_nullhash = _sha(nullid)
def hash(text, p1, p2):
"""generate a hash from the given text and its parent hashes
This hash combines both the current file contents and its history
in a manner that makes it easy to distinguish nodes with the same
content in the revision graph.
"""
# As of now, if one of the parent node is null, p2 is null
if p2 == nullid:
# deep copy of a hash is faster than creating one
s = _nullhash.copy()
s.update(p1)
else:
# none of the parent nodes are nullid
l = [p1, p2]
l.sort()
s = _sha(l[0])
s.update(l[1])
s.update(text)
return s.digest()
def decompress(bin):
""" decompress the given input """
if not bin:
return bin
t = bin[0]
if t == '\0':
return bin
if t == 'x':
try:
return _decompress(bin)
except zlib.error as e:
raise RevlogError(_("revlog decompress error: %s") % str(e))
if t == 'u':
return util.buffer(bin, 1)
raise RevlogError(_("unknown compression type %r") % t)
# index v0:
# 4 bytes: offset
# 4 bytes: compressed length
# 4 bytes: base rev
# 4 bytes: link rev
# 20 bytes: parent 1 nodeid
# 20 bytes: parent 2 nodeid
# 20 bytes: nodeid
indexformatv0 = ">4l20s20s20s"
class revlogoldio(object):
def __init__(self):
self.size = struct.calcsize(indexformatv0)
def parseindex(self, data, inline):
s = self.size
index = []
nodemap = {nullid: nullrev}
n = off = 0
l = len(data)
while off + s <= l:
cur = data[off:off + s]
off += s
e = _unpack(indexformatv0, cur)
# transform to revlogv1 format
e2 = (offset_type(e[0], 0), e[1], -1, e[2], e[3],
nodemap.get(e[4], nullrev), nodemap.get(e[5], nullrev), e[6])
index.append(e2)
nodemap[e[6]] = n
n += 1
# add the magic null revision at -1
index.append((0, 0, 0, -1, -1, -1, -1, nullid))
return index, nodemap, None
def packentry(self, entry, node, version, rev):
if gettype(entry[0]):
raise RevlogError(_("index entry flags need RevlogNG"))
e2 = (getoffset(entry[0]), entry[1], entry[3], entry[4],
node(entry[5]), node(entry[6]), entry[7])
return _pack(indexformatv0, *e2)
# index ng:
# 6 bytes: offset
# 2 bytes: flags
# 4 bytes: compressed length
# 4 bytes: uncompressed length
# 4 bytes: base rev
# 4 bytes: link rev
# 4 bytes: parent 1 rev
# 4 bytes: parent 2 rev
# 32 bytes: nodeid
indexformatng = ">Qiiiiii20s12x"
versionformat = ">I"
# corresponds to uncompressed length of indexformatng (2 gigs, 4-byte
# signed integer)
_maxentrysize = 0x7fffffff
class revlogio(object):
def __init__(self):
self.size = struct.calcsize(indexformatng)
def parseindex(self, data, inline):
# call the C implementation to parse the index data
index, cache = parsers.parse_index2(data, inline)
return index, getattr(index, 'nodemap', None), cache
def packentry(self, entry, node, version, rev):
p = _pack(indexformatng, *entry)
if rev == 0:
p = _pack(versionformat, version) + p[4:]
return p
class revlog(object):
"""
the underlying revision storage object
A revlog consists of two parts, an index and the revision data.
The index is a file with a fixed record size containing
information on each revision, including its nodeid (hash), the
nodeids of its parents, the position and offset of its data within
the data file, and the revision it's based on. Finally, each entry
contains a linkrev entry that can serve as a pointer to external
data.
The revision data itself is a linear collection of data chunks.
Each chunk represents a revision and is usually represented as a
delta against the previous chunk. To bound lookup time, runs of
deltas are limited to about 2 times the length of the original
version data. This makes retrieval of a version proportional to
its size, or O(1) relative to the number of revisions.
Both pieces of the revlog are written to in an append-only
fashion, which means we never need to rewrite a file to insert or
remove data, and can use some simple techniques to avoid the need
for locking while reading.
"""
def __init__(self, opener, indexfile):
"""
create a revlog object
opener is a function that abstracts the file opening operation
and can be used to implement COW semantics or the like.
"""
self.indexfile = indexfile
self.datafile = indexfile[:-2] + ".d"
self.opener = opener
# 3-tuple of (node, rev, text) for a raw revision.
self._cache = None
# 2-tuple of (rev, baserev) defining the base revision the delta chain
# begins at for a revision.
self._basecache = None
# 2-tuple of (offset, data) of raw data from the revlog at an offset.
self._chunkcache = (0, '')
# How much data to read and cache into the raw revlog data cache.
self._chunkcachesize = 65536
self._maxchainlen = None
self._aggressivemergedeltas = False
self.index = []
# Mapping of partial identifiers to full nodes.
self._pcache = {}
# Mapping of revision integer to full node.
self._nodecache = {nullid: nullrev}
self._nodepos = None
v = REVLOG_DEFAULT_VERSION
opts = getattr(opener, 'options', None)
if opts is not None:
if 'revlogv1' in opts:
if 'generaldelta' in opts:
v |= REVLOGGENERALDELTA
else:
v = 0
if 'chunkcachesize' in opts:
self._chunkcachesize = opts['chunkcachesize']
if 'maxchainlen' in opts:
self._maxchainlen = opts['maxchainlen']
if 'aggressivemergedeltas' in opts:
self._aggressivemergedeltas = opts['aggressivemergedeltas']
self._lazydeltabase = bool(opts.get('lazydeltabase', False))
if self._chunkcachesize <= 0:
raise RevlogError(_('revlog chunk cache size %r is not greater '
'than 0') % self._chunkcachesize)
elif self._chunkcachesize & (self._chunkcachesize - 1):
raise RevlogError(_('revlog chunk cache size %r is not a power '
'of 2') % self._chunkcachesize)
indexdata = ''
self._initempty = True
try:
f = self.opener(self.indexfile)
indexdata = f.read()
f.close()
if len(indexdata) > 0:
v = struct.unpack(versionformat, indexdata[:4])[0]
self._initempty = False
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
self.version = v
self._inline = v & REVLOGNGINLINEDATA
self._generaldelta = v & REVLOGGENERALDELTA
flags = v & ~0xFFFF
fmt = v & 0xFFFF
if fmt == REVLOGV0 and flags:
raise RevlogError(_("index %s unknown flags %#04x for format v0")
% (self.indexfile, flags >> 16))
elif fmt == REVLOGNG and flags & ~REVLOGNG_FLAGS:
raise RevlogError(_("index %s unknown flags %#04x for revlogng")
% (self.indexfile, flags >> 16))
elif fmt > REVLOGNG:
raise RevlogError(_("index %s unknown format %d")
% (self.indexfile, fmt))
self._io = revlogio()
if self.version == REVLOGV0:
self._io = revlogoldio()
try:
d = self._io.parseindex(indexdata, self._inline)
except (ValueError, IndexError):
raise RevlogError(_("index %s is corrupted") % (self.indexfile))
self.index, nodemap, self._chunkcache = d
if nodemap is not None:
self.nodemap = self._nodecache = nodemap
if not self._chunkcache:
self._chunkclear()
# revnum -> (chain-length, sum-delta-length)
self._chaininfocache = {}
def tip(self):
return self.node(len(self.index) - 2)
def __contains__(self, rev):
return 0 <= rev < len(self)
def __len__(self):
return len(self.index) - 1
def __iter__(self):
return iter(xrange(len(self)))
def revs(self, start=0, stop=None):
"""iterate over all rev in this revlog (from start to stop)"""
step = 1
if stop is not None:
if start > stop:
step = -1
stop += step
else:
stop = len(self)
return xrange(start, stop, step)
@util.propertycache
def nodemap(self):
self.rev(self.node(0))
return self._nodecache
def hasnode(self, node):
try:
self.rev(node)
return True
except KeyError:
return False
def clearcaches(self):
self._cache = None
self._basecache = None
self._chunkcache = (0, '')
self._pcache = {}
try:
self._nodecache.clearcaches()
except AttributeError:
self._nodecache = {nullid: nullrev}
self._nodepos = None
def rev(self, node):
try:
return self._nodecache[node]
except TypeError:
raise
except RevlogError:
# parsers.c radix tree lookup failed
raise LookupError(node, self.indexfile, _('no node'))
except KeyError:
# pure python cache lookup failed
n = self._nodecache
i = self.index
p = self._nodepos
if p is None:
p = len(i) - 2
for r in xrange(p, -1, -1):
v = i[r][7]
n[v] = r
if v == node:
self._nodepos = r - 1
return r
raise LookupError(node, self.indexfile, _('no node'))
def node(self, rev):
return self.index[rev][7]
def linkrev(self, rev):
return self.index[rev][4]
def parents(self, node):
i = self.index
d = i[self.rev(node)]
return i[d[5]][7], i[d[6]][7] # map revisions to nodes inline
def parentrevs(self, rev):
return self.index[rev][5:7]
def start(self, rev):
return int(self.index[rev][0] >> 16)
def end(self, rev):
return self.start(rev) + self.length(rev)
def length(self, rev):
return self.index[rev][1]
def chainbase(self, rev):
index = self.index
base = index[rev][3]
while base != rev:
rev = base
base = index[rev][3]
return base
def chainlen(self, rev):
return self._chaininfo(rev)[0]
def _chaininfo(self, rev):
chaininfocache = self._chaininfocache
if rev in chaininfocache:
return chaininfocache[rev]
index = self.index
generaldelta = self._generaldelta
iterrev = rev
e = index[iterrev]
clen = 0
compresseddeltalen = 0
while iterrev != e[3]:
clen += 1
compresseddeltalen += e[1]
if generaldelta:
iterrev = e[3]
else:
iterrev -= 1
if iterrev in chaininfocache:
t = chaininfocache[iterrev]
clen += t[0]
compresseddeltalen += t[1]
break
e = index[iterrev]
else:
# Add text length of base since decompressing that also takes
# work. For cache hits the length is already included.
compresseddeltalen += e[1]
r = (clen, compresseddeltalen)
chaininfocache[rev] = r
return r
def _deltachain(self, rev, stoprev=None):
"""Obtain the delta chain for a revision.
``stoprev`` specifies a revision to stop at. If not specified, we
stop at the base of the chain.
Returns a 2-tuple of (chain, stopped) where ``chain`` is a list of
revs in ascending order and ``stopped`` is a bool indicating whether
``stoprev`` was hit.
"""
chain = []
# Alias to prevent attribute lookup in tight loop.
index = self.index
generaldelta = self._generaldelta
iterrev = rev
e = index[iterrev]
while iterrev != e[3] and iterrev != stoprev:
chain.append(iterrev)
if generaldelta:
iterrev = e[3]
else:
iterrev -= 1
e = index[iterrev]
if iterrev == stoprev:
stopped = True
else:
chain.append(iterrev)
stopped = False
chain.reverse()
return chain, stopped
def flags(self, rev):
return self.index[rev][0] & 0xFFFF
def rawsize(self, rev):
"""return the length of the uncompressed text for a given revision"""
l = self.index[rev][2]
if l >= 0:
return l
t = self.revision(self.node(rev))
return len(t)
size = rawsize
def ancestors(self, revs, stoprev=0, inclusive=False):
"""Generate the ancestors of 'revs' in reverse topological order.
Does not generate revs lower than stoprev.
See the documentation for ancestor.lazyancestors for more details."""
return ancestor.lazyancestors(self.parentrevs, revs, stoprev=stoprev,
inclusive=inclusive)
def descendants(self, revs):
"""Generate the descendants of 'revs' in revision order.
Yield a sequence of revision numbers starting with a child of
some rev in revs, i.e., each revision is *not* considered a
descendant of itself. Results are ordered by revision number (a
topological sort)."""
first = min(revs)
if first == nullrev:
for i in self:
yield i
return
seen = set(revs)
for i in self.revs(start=first + 1):
for x in self.parentrevs(i):
if x != nullrev and x in seen:
seen.add(i)
yield i
break
def findcommonmissing(self, common=None, heads=None):
"""Return a tuple of the ancestors of common and the ancestors of heads
that are not ancestors of common. In revset terminology, we return the
tuple:
::common, (::heads) - (::common)
The list is sorted by revision number, meaning it is
topologically sorted.
'heads' and 'common' are both lists of node IDs. If heads is
not supplied, uses all of the revlog's heads. If common is not
supplied, uses nullid."""
if common is None:
common = [nullid]
if heads is None:
heads = self.heads()
common = [self.rev(n) for n in common]
heads = [self.rev(n) for n in heads]
# we want the ancestors, but inclusive
class lazyset(object):
def __init__(self, lazyvalues):
self.addedvalues = set()
self.lazyvalues = lazyvalues
def __contains__(self, value):
return value in self.addedvalues or value in self.lazyvalues
def __iter__(self):
added = self.addedvalues
for r in added:
yield r
for r in self.lazyvalues:
if not r in added:
yield r
def add(self, value):
self.addedvalues.add(value)
def update(self, values):
self.addedvalues.update(values)
has = lazyset(self.ancestors(common))
has.add(nullrev)
has.update(common)
# take all ancestors from heads that aren't in has
missing = set()
visit = collections.deque(r for r in heads if r not in has)
while visit:
r = visit.popleft()
if r in missing:
continue
else:
missing.add(r)
for p in self.parentrevs(r):
if p not in has:
visit.append(p)
missing = list(missing)
missing.sort()
return has, [self.node(r) for r in missing]
def incrementalmissingrevs(self, common=None):
"""Return an object that can be used to incrementally compute the
revision numbers of the ancestors of arbitrary sets that are not
ancestors of common. This is an ancestor.incrementalmissingancestors
object.
'common' is a list of revision numbers. If common is not supplied, uses
nullrev.
"""
if common is None:
common = [nullrev]
return ancestor.incrementalmissingancestors(self.parentrevs, common)
def findmissingrevs(self, common=None, heads=None):
"""Return the revision numbers of the ancestors of heads that
are not ancestors of common.
More specifically, return a list of revision numbers corresponding to
nodes N such that every N satisfies the following constraints:
1. N is an ancestor of some node in 'heads'
2. N is not an ancestor of any node in 'common'
The list is sorted by revision number, meaning it is
topologically sorted.
'heads' and 'common' are both lists of revision numbers. If heads is
not supplied, uses all of the revlog's heads. If common is not
supplied, uses nullid."""
if common is None:
common = [nullrev]
if heads is None:
heads = self.headrevs()
inc = self.incrementalmissingrevs(common=common)
return inc.missingancestors(heads)
def findmissing(self, common=None, heads=None):
"""Return the ancestors of heads that are not ancestors of common.
More specifically, return a list of nodes N such that every N
satisfies the following constraints:
1. N is an ancestor of some node in 'heads'
2. N is not an ancestor of any node in 'common'
The list is sorted by revision number, meaning it is
topologically sorted.
'heads' and 'common' are both lists of node IDs. If heads is
not supplied, uses all of the revlog's heads. If common is not
supplied, uses nullid."""
if common is None:
common = [nullid]
if heads is None:
heads = self.heads()
common = [self.rev(n) for n in common]
heads = [self.rev(n) for n in heads]
inc = self.incrementalmissingrevs(common=common)
return [self.node(r) for r in inc.missingancestors(heads)]
def nodesbetween(self, roots=None, heads=None):
"""Return a topological path from 'roots' to 'heads'.
Return a tuple (nodes, outroots, outheads) where 'nodes' is a
topologically sorted list of all nodes N that satisfy both of
these constraints:
1. N is a descendant of some node in 'roots'
2. N is an ancestor of some node in 'heads'
Every node is considered to be both a descendant and an ancestor
of itself, so every reachable node in 'roots' and 'heads' will be
included in 'nodes'.
'outroots' is the list of reachable nodes in 'roots', i.e., the
subset of 'roots' that is returned in 'nodes'. Likewise,
'outheads' is the subset of 'heads' that is also in 'nodes'.
'roots' and 'heads' are both lists of node IDs. If 'roots' is
unspecified, uses nullid as the only root. If 'heads' is
unspecified, uses list of all of the revlog's heads."""
nonodes = ([], [], [])
if roots is not None:
roots = list(roots)
if not roots:
return nonodes
lowestrev = min([self.rev(n) for n in roots])
else:
roots = [nullid] # Everybody's a descendant of nullid
lowestrev = nullrev
if (lowestrev == nullrev) and (heads is None):
# We want _all_ the nodes!
return ([self.node(r) for r in self], [nullid], list(self.heads()))
if heads is None:
# All nodes are ancestors, so the latest ancestor is the last
# node.
highestrev = len(self) - 1
# Set ancestors to None to signal that every node is an ancestor.
ancestors = None
# Set heads to an empty dictionary for later discovery of heads
heads = {}
else:
heads = list(heads)
if not heads:
return nonodes
ancestors = set()
# Turn heads into a dictionary so we can remove 'fake' heads.
# Also, later we will be using it to filter out the heads we can't
# find from roots.
heads = dict.fromkeys(heads, False)
# Start at the top and keep marking parents until we're done.
nodestotag = set(heads)
# Remember where the top was so we can use it as a limit later.
highestrev = max([self.rev(n) for n in nodestotag])
while nodestotag:
# grab a node to tag
n = nodestotag.pop()
# Never tag nullid
if n == nullid:
continue
# A node's revision number represents its place in a
# topologically sorted list of nodes.
r = self.rev(n)
if r >= lowestrev:
if n not in ancestors:
# If we are possibly a descendant of one of the roots
# and we haven't already been marked as an ancestor
ancestors.add(n) # Mark as ancestor
# Add non-nullid parents to list of nodes to tag.
nodestotag.update([p for p in self.parents(n) if
p != nullid])
elif n in heads: # We've seen it before, is it a fake head?
# So it is, real heads should not be the ancestors of
# any other heads.
heads.pop(n)
if not ancestors:
return nonodes
# Now that we have our set of ancestors, we want to remove any
# roots that are not ancestors.
# If one of the roots was nullid, everything is included anyway.
if lowestrev > nullrev:
# But, since we weren't, let's recompute the lowest rev to not
# include roots that aren't ancestors.
# Filter out roots that aren't ancestors of heads
roots = [n for n in roots if n in ancestors]
# Recompute the lowest revision
if roots:
lowestrev = min([self.rev(n) for n in roots])
else:
# No more roots? Return empty list
return nonodes
else:
# We are descending from nullid, and don't need to care about
# any other roots.
lowestrev = nullrev
roots = [nullid]
# Transform our roots list into a set.
descendants = set(roots)
# Also, keep the original roots so we can filter out roots that aren't
# 'real' roots (i.e. are descended from other roots).
roots = descendants.copy()
# Our topologically sorted list of output nodes.
orderedout = []
# Don't start at nullid since we don't want nullid in our output list,
# and if nullid shows up in descendants, empty parents will look like
# they're descendants.
for r in self.revs(start=max(lowestrev, 0), stop=highestrev + 1):
n = self.node(r)
isdescendant = False
if lowestrev == nullrev: # Everybody is a descendant of nullid
isdescendant = True
elif n in descendants:
# n is already a descendant
isdescendant = True
# This check only needs to be done here because all the roots
# will start being marked is descendants before the loop.
if n in roots:
# If n was a root, check if it's a 'real' root.
p = tuple(self.parents(n))
# If any of its parents are descendants, it's not a root.
if (p[0] in descendants) or (p[1] in descendants):
roots.remove(n)
else:
p = tuple(self.parents(n))
# A node is a descendant if either of its parents are
# descendants. (We seeded the dependents list with the roots
# up there, remember?)
if (p[0] in descendants) or (p[1] in descendants):
descendants.add(n)
isdescendant = True
if isdescendant and ((ancestors is None) or (n in ancestors)):
# Only include nodes that are both descendants and ancestors.
orderedout.append(n)
if (ancestors is not None) and (n in heads):
# We're trying to figure out which heads are reachable
# from roots.
# Mark this head as having been reached
heads[n] = True
elif ancestors is None:
# Otherwise, we're trying to discover the heads.
# Assume this is a head because if it isn't, the next step
# will eventually remove it.
heads[n] = True
# But, obviously its parents aren't.
for p in self.parents(n):
heads.pop(p, None)
heads = [n for n, flag in heads.iteritems() if flag]
roots = list(roots)
assert orderedout
assert roots
assert heads
return (orderedout, roots, heads)
def headrevs(self):
try:
return self.index.headrevs()
except AttributeError:
return self._headrevs()
def computephases(self, roots):
return self.index.computephasesmapsets(roots)
def _headrevs(self):
count = len(self)
if not count:
return [nullrev]
# we won't iter over filtered rev so nobody is a head at start
ishead = [0] * (count + 1)
index = self.index
for r in self:
ishead[r] = 1 # I may be an head
e = index[r]
ishead[e[5]] = ishead[e[6]] = 0 # my parent are not
return [r for r, val in enumerate(ishead) if val]
def heads(self, start=None, stop=None):
"""return the list of all nodes that have no children
if start is specified, only heads that are descendants of
start will be returned
if stop is specified, it will consider all the revs from stop
as if they had no children
"""
if start is None and stop is None:
if not len(self):
return [nullid]
return [self.node(r) for r in self.headrevs()]
if start is None:
start = nullid
if stop is None:
stop = []
stoprevs = set([self.rev(n) for n in stop])
startrev = self.rev(start)
reachable = set((startrev,))
heads = set((startrev,))
parentrevs = self.parentrevs
for r in self.revs(start=startrev + 1):
for p in parentrevs(r):
if p in reachable:
if r not in stoprevs:
reachable.add(r)
heads.add(r)
if p in heads and p not in stoprevs:
heads.remove(p)
return [self.node(r) for r in heads]
def children(self, node):
"""find the children of a given node"""
c = []
p = self.rev(node)
for r in self.revs(start=p + 1):
prevs = [pr for pr in self.parentrevs(r) if pr != nullrev]
if prevs:
for pr in prevs:
if pr == p:
c.append(self.node(r))
elif p == nullrev:
c.append(self.node(r))
return c
def descendant(self, start, end):
if start == nullrev:
return True
for i in self.descendants([start]):
if i == end:
return True
elif i > end:
break
return False
def commonancestorsheads(self, a, b):
"""calculate all the heads of the common ancestors of nodes a and b"""
a, b = self.rev(a), self.rev(b)
try:
ancs = self.index.commonancestorsheads(a, b)
except (AttributeError, OverflowError): # C implementation failed
ancs = ancestor.commonancestorsheads(self.parentrevs, a, b)
return map(self.node, ancs)
def isancestor(self, a, b):
"""return True if node a is an ancestor of node b
The implementation of this is trivial but the use of
commonancestorsheads is not."""
return a in self.commonancestorsheads(a, b)
def ancestor(self, a, b):
"""calculate the "best" common ancestor of nodes a and b"""
a, b = self.rev(a), self.rev(b)
try:
ancs = self.index.ancestors(a, b)
except (AttributeError, OverflowError):
ancs = ancestor.ancestors(self.parentrevs, a, b)
if ancs:
# choose a consistent winner when there's a tie
return min(map(self.node, ancs))
return nullid
def _match(self, id):
if isinstance(id, int):
# rev
return self.node(id)
if len(id) == 20:
# possibly a binary node
# odds of a binary node being all hex in ASCII are 1 in 10**25
try:
node = id
self.rev(node) # quick search the index
return node
except LookupError:
pass # may be partial hex id
try:
# str(rev)
rev = int(id)
if str(rev) != id:
raise ValueError
if rev < 0:
rev = len(self) + rev
if rev < 0 or rev >= len(self):
raise ValueError
return self.node(rev)
except (ValueError, OverflowError):
pass
if len(id) == 40:
try:
# a full hex nodeid?
node = bin(id)
self.rev(node)
return node
except (TypeError, LookupError):
pass
def _partialmatch(self, id):
try:
n = self.index.partialmatch(id)
if n and self.hasnode(n):
return n
return None
except RevlogError:
# parsers.c radix tree lookup gave multiple matches
# fall through to slow path that filters hidden revisions
pass
except (AttributeError, ValueError):
# we are pure python, or key was too short to search radix tree
pass
if id in self._pcache:
return self._pcache[id]
if len(id) < 40:
try:
# hex(node)[:...]
l = len(id) // 2 # grab an even number of digits
prefix = bin(id[:l * 2])
nl = [e[7] for e in self.index if e[7].startswith(prefix)]
nl = [n for n in nl if hex(n).startswith(id) and
self.hasnode(n)]
if len(nl) > 0:
if len(nl) == 1:
self._pcache[id] = nl[0]
return nl[0]
raise LookupError(id, self.indexfile,
_('ambiguous identifier'))
return None
except TypeError:
pass
def lookup(self, id):
"""locate a node based on:
- revision number or str(revision number)
- nodeid or subset of hex nodeid
"""
n = self._match(id)
if n is not None:
return n
n = self._partialmatch(id)
if n:
return n
raise LookupError(id, self.indexfile, _('no match found'))
def cmp(self, node, text):
"""compare text with a given file revision
returns True if text is different than what is stored.
"""
p1, p2 = self.parents(node)
return hash(text, p1, p2) != node
def _addchunk(self, offset, data):
"""Add a segment to the revlog cache.
Accepts an absolute offset and the data that is at that location.
"""
o, d = self._chunkcache
# try to add to existing cache
if o + len(d) == offset and len(d) + len(data) < _chunksize:
self._chunkcache = o, d + data
else:
self._chunkcache = offset, data
def _loadchunk(self, offset, length, df=None):
"""Load a segment of raw data from the revlog.
Accepts an absolute offset, length to read, and an optional existing
file handle to read from.
If an existing file handle is passed, it will be seeked and the
original seek position will NOT be restored.
Returns a str or buffer of raw byte data.
"""
if df is not None:
closehandle = False
else:
if self._inline:
df = self.opener(self.indexfile)
else:
df = self.opener(self.datafile)
closehandle = True
# Cache data both forward and backward around the requested
# data, in a fixed size window. This helps speed up operations
# involving reading the revlog backwards.
cachesize = self._chunkcachesize
realoffset = offset & ~(cachesize - 1)
reallength = (((offset + length + cachesize) & ~(cachesize - 1))
- realoffset)
df.seek(realoffset)
d = df.read(reallength)
if closehandle:
df.close()
self._addchunk(realoffset, d)
if offset != realoffset or reallength != length:
return util.buffer(d, offset - realoffset, length)
return d
def _getchunk(self, offset, length, df=None):
"""Obtain a segment of raw data from the revlog.
Accepts an absolute offset, length of bytes to obtain, and an
optional file handle to the already-opened revlog. If the file
handle is used, it's original seek position will not be preserved.
Requests for data may be returned from a cache.
Returns a str or a buffer instance of raw byte data.
"""
o, d = self._chunkcache
l = len(d)
# is it in the cache?
cachestart = offset - o
cacheend = cachestart + length
if cachestart >= 0 and cacheend <= l:
if cachestart == 0 and cacheend == l:
return d # avoid a copy
return util.buffer(d, cachestart, cacheend - cachestart)
return self._loadchunk(offset, length, df=df)
def _chunkraw(self, startrev, endrev, df=None):
"""Obtain a segment of raw data corresponding to a range of revisions.
Accepts the start and end revisions and an optional already-open
file handle to be used for reading. If the file handle is read, its
seek position will not be preserved.
Requests for data may be satisfied by a cache.
Returns a 2-tuple of (offset, data) for the requested range of
revisions. Offset is the integer offset from the beginning of the
revlog and data is a str or buffer of the raw byte data.
Callers will need to call ``self.start(rev)`` and ``self.length(rev)``
to determine where each revision's data begins and ends.
"""
start = self.start(startrev)
end = self.end(endrev)
if self._inline:
start += (startrev + 1) * self._io.size
end += (endrev + 1) * self._io.size
length = end - start
return start, self._getchunk(start, length, df=df)
def _chunk(self, rev, df=None):
"""Obtain a single decompressed chunk for a revision.
Accepts an integer revision and an optional already-open file handle
to be used for reading. If used, the seek position of the file will not
be preserved.
Returns a str holding uncompressed data for the requested revision.
"""
return decompress(self._chunkraw(rev, rev, df=df)[1])
def _chunks(self, revs, df=None):
"""Obtain decompressed chunks for the specified revisions.
Accepts an iterable of numeric revisions that are assumed to be in
ascending order. Also accepts an optional already-open file handle
to be used for reading. If used, the seek position of the file will
not be preserved.
This function is similar to calling ``self._chunk()`` multiple times,
but is faster.
Returns a list with decompressed data for each requested revision.
"""
if not revs:
return []
start = self.start
length = self.length
inline = self._inline
iosize = self._io.size
buffer = util.buffer
l = []
ladd = l.append
try:
offset, data = self._chunkraw(revs[0], revs[-1], df=df)
except OverflowError:
# issue4215 - we can't cache a run of chunks greater than
# 2G on Windows
return [self._chunk(rev, df=df) for rev in revs]
for rev in revs:
chunkstart = start(rev)
if inline:
chunkstart += (rev + 1) * iosize
chunklength = length(rev)
ladd(decompress(buffer(data, chunkstart - offset, chunklength)))
return l
def _chunkclear(self):
"""Clear the raw chunk cache."""
self._chunkcache = (0, '')
def deltaparent(self, rev):
"""return deltaparent of the given revision"""
base = self.index[rev][3]
if base == rev:
return nullrev
elif self._generaldelta:
return base
else:
return rev - 1
def revdiff(self, rev1, rev2):
"""return or calculate a delta between two revisions"""
if rev1 != nullrev and self.deltaparent(rev2) == rev1:
return str(self._chunk(rev2))
return mdiff.textdiff(self.revision(rev1),
self.revision(rev2))
def revision(self, nodeorrev, _df=None):
"""return an uncompressed revision of a given node or revision
number.
_df is an existing file handle to read from. It is meant to only be
used internally.
"""
if isinstance(nodeorrev, int):
rev = nodeorrev
node = self.node(rev)
else:
node = nodeorrev
rev = None
cachedrev = None
if node == nullid:
return ""
if self._cache:
if self._cache[0] == node:
return self._cache[2]
cachedrev = self._cache[1]
# look up what we need to read
text = None
if rev is None:
rev = self.rev(node)
# check rev flags
if self.flags(rev) & ~REVIDX_KNOWN_FLAGS:
raise RevlogError(_('incompatible revision flag %x') %
(self.flags(rev) & ~REVIDX_KNOWN_FLAGS))
chain, stopped = self._deltachain(rev, stoprev=cachedrev)
if stopped:
text = self._cache[2]
# drop cache to save memory
self._cache = None
bins = self._chunks(chain, df=_df)
if text is None:
text = str(bins[0])
bins = bins[1:]
text = mdiff.patches(text, bins)
text = self._checkhash(text, node, rev)
self._cache = (node, rev, text)
return text
def hash(self, text, p1, p2):
"""Compute a node hash.
Available as a function so that subclasses can replace the hash
as needed.
"""
return hash(text, p1, p2)
def _checkhash(self, text, node, rev):
p1, p2 = self.parents(node)
self.checkhash(text, p1, p2, node, rev)
return text
def checkhash(self, text, p1, p2, node, rev=None):
if node != self.hash(text, p1, p2):
revornode = rev
if revornode is None:
revornode = templatefilters.short(hex(node))
raise RevlogError(_("integrity check failed on %s:%s")
% (self.indexfile, revornode))
def checkinlinesize(self, tr, fp=None):
"""Check if the revlog is too big for inline and convert if so.
This should be called after revisions are added to the revlog. If the
revlog has grown too large to be an inline revlog, it will convert it
to use multiple index and data files.
"""
if not self._inline or (self.start(-2) + self.length(-2)) < _maxinline:
return
trinfo = tr.find(self.indexfile)
if trinfo is None:
raise RevlogError(_("%s not found in the transaction")
% self.indexfile)
trindex = trinfo[2]
if trindex is not None:
dataoff = self.start(trindex)
else:
# revlog was stripped at start of transaction, use all leftover data
trindex = len(self) - 1
dataoff = self.end(-2)
tr.add(self.datafile, dataoff)
if fp:
fp.flush()
fp.close()
df = self.opener(self.datafile, 'w')
try:
for r in self:
df.write(self._chunkraw(r, r)[1])
finally:
df.close()
fp = self.opener(self.indexfile, 'w', atomictemp=True)
self.version &= ~(REVLOGNGINLINEDATA)
self._inline = False
for i in self:
e = self._io.packentry(self.index[i], self.node, self.version, i)
fp.write(e)
# if we don't call close, the temp file will never replace the
# real index
fp.close()
tr.replace(self.indexfile, trindex * self._io.size)
self._chunkclear()
def addrevision(self, text, transaction, link, p1, p2, cachedelta=None,
node=None):
"""add a revision to the log
text - the revision data to add
transaction - the transaction object used for rollback
link - the linkrev data to add
p1, p2 - the parent nodeids of the revision
cachedelta - an optional precomputed delta
node - nodeid of revision; typically node is not specified, and it is
computed by default as hash(text, p1, p2), however subclasses might
use different hashing method (and override checkhash() in such case)
"""
if link == nullrev:
raise RevlogError(_("attempted to add linkrev -1 to %s")
% self.indexfile)
if len(text) > _maxentrysize:
raise RevlogError(
_("%s: size of %d bytes exceeds maximum revlog storage of 2GiB")
% (self.indexfile, len(text)))
node = node or self.hash(text, p1, p2)
if node in self.nodemap:
return node
dfh = None
if not self._inline:
dfh = self.opener(self.datafile, "a+")
ifh = self.opener(self.indexfile, "a+")
try:
return self._addrevision(node, text, transaction, link, p1, p2,
REVIDX_DEFAULT_FLAGS, cachedelta, ifh, dfh)
finally:
if dfh:
dfh.close()
ifh.close()
def compress(self, text):
""" generate a possibly-compressed representation of text """
if not text:
return ("", text)
l = len(text)
bin = None
if l < 44:
pass
elif l > 1000000:
# zlib makes an internal copy, thus doubling memory usage for
# large files, so lets do this in pieces
z = zlib.compressobj()
p = []
pos = 0
while pos < l:
pos2 = pos + 2**20
p.append(z.compress(text[pos:pos2]))
pos = pos2
p.append(z.flush())
if sum(map(len, p)) < l:
bin = "".join(p)
else:
bin = _compress(text)
if bin is None or len(bin) > l:
if text[0] == '\0':
return ("", text)
return ('u', text)
return ("", bin)
def _isgooddelta(self, d, textlen):
"""Returns True if the given delta is good. Good means that it is within
the disk span, disk size, and chain length bounds that we know to be
performant."""
if d is None:
return False
# - 'dist' is the distance from the base revision -- bounding it limits
# the amount of I/O we need to do.
# - 'compresseddeltalen' is the sum of the total size of deltas we need
# to apply -- bounding it limits the amount of CPU we consume.
dist, l, data, base, chainbase, chainlen, compresseddeltalen = d
if (dist > textlen * 4 or l > textlen or
compresseddeltalen > textlen * 2 or
(self._maxchainlen and chainlen > self._maxchainlen)):
return False
return True
def _addrevision(self, node, text, transaction, link, p1, p2, flags,
cachedelta, ifh, dfh, alwayscache=False):
"""internal function to add revisions to the log
see addrevision for argument descriptions.
invariants:
- text is optional (can be None); if not set, cachedelta must be set.
if both are set, they must correspond to each other.
"""
btext = [text]
def buildtext():
if btext[0] is not None:
return btext[0]
baserev = cachedelta[0]
delta = cachedelta[1]
# special case deltas which replace entire base; no need to decode
# base revision. this neatly avoids censored bases, which throw when
# they're decoded.
hlen = struct.calcsize(">lll")
if delta[:hlen] == mdiff.replacediffheader(self.rawsize(baserev),
len(delta) - hlen):
btext[0] = delta[hlen:]
else:
if self._inline:
fh = ifh
else:
fh = dfh
basetext = self.revision(self.node(baserev), _df=fh)
btext[0] = mdiff.patch(basetext, delta)
try:
self.checkhash(btext[0], p1, p2, node)
if flags & REVIDX_ISCENSORED:
raise RevlogError(_('node %s is not censored') % node)
except CensoredNodeError:
# must pass the censored index flag to add censored revisions
if not flags & REVIDX_ISCENSORED:
raise
return btext[0]
def builddelta(rev):
# can we use the cached delta?
if cachedelta and cachedelta[0] == rev:
delta = cachedelta[1]
else:
t = buildtext()
if self.iscensored(rev):
# deltas based on a censored revision must replace the
# full content in one patch, so delta works everywhere
header = mdiff.replacediffheader(self.rawsize(rev), len(t))
delta = header + t
else:
if self._inline:
fh = ifh
else:
fh = dfh
ptext = self.revision(self.node(rev), _df=fh)
delta = mdiff.textdiff(ptext, t)
data = self.compress(delta)
l = len(data[1]) + len(data[0])
if basecache[0] == rev:
chainbase = basecache[1]
else:
chainbase = self.chainbase(rev)
dist = l + offset - self.start(chainbase)
if self._generaldelta:
base = rev
else:
base = chainbase
chainlen, compresseddeltalen = self._chaininfo(rev)
chainlen += 1
compresseddeltalen += l
return dist, l, data, base, chainbase, chainlen, compresseddeltalen
curr = len(self)
prev = curr - 1
base = chainbase = curr
offset = self.end(prev)
delta = None
if self._basecache is None:
self._basecache = (prev, self.chainbase(prev))
basecache = self._basecache
p1r, p2r = self.rev(p1), self.rev(p2)
# full versions are inserted when the needed deltas
# become comparable to the uncompressed text
if text is None:
textlen = mdiff.patchedsize(self.rawsize(cachedelta[0]),
cachedelta[1])
else:
textlen = len(text)
# should we try to build a delta?
if prev != nullrev:
tested = set()
if cachedelta and self._generaldelta and self._lazydeltabase:
# Assume what we received from the server is a good choice
# build delta will reuse the cache
candidatedelta = builddelta(cachedelta[0])
tested.add(cachedelta[0])
if self._isgooddelta(candidatedelta, textlen):
delta = candidatedelta
if delta is None and self._generaldelta:
# exclude already lazy tested base if any
parents = [p for p in (p1r, p2r)
if p != nullrev and p not in tested]
if parents and not self._aggressivemergedeltas:
# Pick whichever parent is closer to us (to minimize the
# chance of having to build a fulltext).
parents = [max(parents)]
tested.update(parents)
pdeltas = []
for p in parents:
pd = builddelta(p)
if self._isgooddelta(pd, textlen):
pdeltas.append(pd)
if pdeltas:
delta = min(pdeltas, key=lambda x: x[1])
if delta is None and prev not in tested:
# other approach failed try against prev to hopefully save us a
# fulltext.
candidatedelta = builddelta(prev)
if self._isgooddelta(candidatedelta, textlen):
delta = candidatedelta
if delta is not None:
dist, l, data, base, chainbase, chainlen, compresseddeltalen = delta
else:
text = buildtext()
data = self.compress(text)
l = len(data[1]) + len(data[0])
base = chainbase = curr
e = (offset_type(offset, flags), l, textlen,
base, link, p1r, p2r, node)
self.index.insert(-1, e)
self.nodemap[node] = curr
entry = self._io.packentry(e, self.node, self.version, curr)
self._writeentry(transaction, ifh, dfh, entry, data, link, offset)
if alwayscache and text is None:
text = buildtext()
if type(text) == str: # only accept immutable objects
self._cache = (node, curr, text)
self._basecache = (curr, chainbase)
return node
def _writeentry(self, transaction, ifh, dfh, entry, data, link, offset):
# Files opened in a+ mode have inconsistent behavior on various
# platforms. Windows requires that a file positioning call be made
# when the file handle transitions between reads and writes. See
# 3686fa2b8eee and the mixedfilemodewrapper in windows.py. On other
# platforms, Python or the platform itself can be buggy. Some versions
# of Solaris have been observed to not append at the end of the file
# if the file was seeked to before the end. See issue4943 for more.
#
# We work around this issue by inserting a seek() before writing.
# Note: This is likely not necessary on Python 3.
ifh.seek(0, os.SEEK_END)
if dfh:
dfh.seek(0, os.SEEK_END)
curr = len(self) - 1
if not self._inline:
transaction.add(self.datafile, offset)
transaction.add(self.indexfile, curr * len(entry))
if data[0]:
dfh.write(data[0])
dfh.write(data[1])
ifh.write(entry)
else:
offset += curr * self._io.size
transaction.add(self.indexfile, offset, curr)
ifh.write(entry)
ifh.write(data[0])
ifh.write(data[1])
self.checkinlinesize(transaction, ifh)
def addgroup(self, cg, linkmapper, transaction, addrevisioncb=None):
"""
add a delta group
given a set of deltas, add them to the revision log. the
first delta is against its parent, which should be in our
log, the rest are against the previous delta.
If ``addrevisioncb`` is defined, it will be called with arguments of
this revlog and the node that was added.
"""
# track the base of the current delta log
content = []
node = None
r = len(self)
end = 0
if r:
end = self.end(r - 1)
ifh = self.opener(self.indexfile, "a+")
isize = r * self._io.size
if self._inline:
transaction.add(self.indexfile, end + isize, r)
dfh = None
else:
transaction.add(self.indexfile, isize, r)
transaction.add(self.datafile, end)
dfh = self.opener(self.datafile, "a+")
def flush():
if dfh:
dfh.flush()
ifh.flush()
try:
# loop through our set of deltas
chain = None
while True:
chunkdata = cg.deltachunk(chain)
if not chunkdata:
break
node = chunkdata['node']
p1 = chunkdata['p1']
p2 = chunkdata['p2']
cs = chunkdata['cs']
deltabase = chunkdata['deltabase']
delta = chunkdata['delta']
flags = chunkdata['flags'] or REVIDX_DEFAULT_FLAGS
content.append(node)
link = linkmapper(cs)
if node in self.nodemap:
# this can happen if two branches make the same change
chain = node
continue
for p in (p1, p2):
if p not in self.nodemap:
raise LookupError(p, self.indexfile,
_('unknown parent'))
if deltabase not in self.nodemap:
raise LookupError(deltabase, self.indexfile,
_('unknown delta base'))
baserev = self.rev(deltabase)
if baserev != nullrev and self.iscensored(baserev):
# if base is censored, delta must be full replacement in a
# single patch operation
hlen = struct.calcsize(">lll")
oldlen = self.rawsize(baserev)
newlen = len(delta) - hlen
if delta[:hlen] != mdiff.replacediffheader(oldlen, newlen):
raise error.CensoredBaseError(self.indexfile,
self.node(baserev))
if not flags and self._peek_iscensored(baserev, delta, flush):
flags |= REVIDX_ISCENSORED
# We assume consumers of addrevisioncb will want to retrieve
# the added revision, which will require a call to
# revision(). revision() will fast path if there is a cache
# hit. So, we tell _addrevision() to always cache in this case.
chain = self._addrevision(node, None, transaction, link,
p1, p2, flags, (baserev, delta),
ifh, dfh,
alwayscache=bool(addrevisioncb))
if addrevisioncb:
addrevisioncb(self, chain)
if not dfh and not self._inline:
# addrevision switched from inline to conventional
# reopen the index
ifh.close()
dfh = self.opener(self.datafile, "a+")
ifh = self.opener(self.indexfile, "a+")
finally:
if dfh:
dfh.close()
ifh.close()
return content
def iscensored(self, rev):
"""Check if a file revision is censored."""
return False
def _peek_iscensored(self, baserev, delta, flush):
"""Quickly check if a delta produces a censored revision."""
return False
def getstrippoint(self, minlink):
"""find the minimum rev that must be stripped to strip the linkrev
Returns a tuple containing the minimum rev and a set of all revs that
have linkrevs that will be broken by this strip.
"""
brokenrevs = set()
strippoint = len(self)
heads = {}
futurelargelinkrevs = set()
for head in self.headrevs():
headlinkrev = self.linkrev(head)
heads[head] = headlinkrev
if headlinkrev >= minlink:
futurelargelinkrevs.add(headlinkrev)
# This algorithm involves walking down the rev graph, starting at the
# heads. Since the revs are topologically sorted according to linkrev,
# once all head linkrevs are below the minlink, we know there are
# no more revs that could have a linkrev greater than minlink.
# So we can stop walking.
while futurelargelinkrevs:
strippoint -= 1
linkrev = heads.pop(strippoint)
if linkrev < minlink:
brokenrevs.add(strippoint)
else:
futurelargelinkrevs.remove(linkrev)
for p in self.parentrevs(strippoint):
if p != nullrev:
plinkrev = self.linkrev(p)
heads[p] = plinkrev
if plinkrev >= minlink:
futurelargelinkrevs.add(plinkrev)
return strippoint, brokenrevs
def strip(self, minlink, transaction):
"""truncate the revlog on the first revision with a linkrev >= minlink
This function is called when we're stripping revision minlink and
its descendants from the repository.
We have to remove all revisions with linkrev >= minlink, because
the equivalent changelog revisions will be renumbered after the
strip.
So we truncate the revlog on the first of these revisions, and
trust that the caller has saved the revisions that shouldn't be
removed and that it'll re-add them after this truncation.
"""
if len(self) == 0:
return
rev, _ = self.getstrippoint(minlink)
if rev == len(self):
return
# first truncate the files on disk
end = self.start(rev)
if not self._inline:
transaction.add(self.datafile, end)
end = rev * self._io.size
else:
end += rev * self._io.size
transaction.add(self.indexfile, end)
# then reset internal state in memory to forget those revisions
self._cache = None
self._chaininfocache = {}
self._chunkclear()
for x in xrange(rev, len(self)):
del self.nodemap[self.node(x)]
del self.index[rev:-1]
def checksize(self):
expected = 0
if len(self):
expected = max(0, self.end(len(self) - 1))
try:
f = self.opener(self.datafile)
f.seek(0, 2)
actual = f.tell()
f.close()
dd = actual - expected
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
dd = 0
try:
f = self.opener(self.indexfile)
f.seek(0, 2)
actual = f.tell()
f.close()
s = self._io.size
i = max(0, actual // s)
di = actual - (i * s)
if self._inline:
databytes = 0
for r in self:
databytes += max(0, self.length(r))
dd = 0
di = actual - len(self) * s - databytes
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
di = 0
return (dd, di)
def files(self):
res = [self.indexfile]
if not self._inline:
res.append(self.datafile)
return res